I have 2 CO ECV vouchers which I'd like to use for a flight priced at about $1250. One is residual funds from a reservation, one is a bump voucher. I tried to redeem 2 online, but it proved to be not possible. I called, they refused to do it.

So I was wondering if this workaround would allow me to use a second voucher.

1) Book a refundable CO reservation, using the PIN from the travel funds.

2) Try to use the change reservation function to purchase flight I actually want, in the process, use the bump voucher (+credit card) to pay the difference.

Anyone know if this is possible?